1. Field of the Invention
This invention relates to an improvement of method for manufacturing a laminated plate used in a semiconductor device.
As shown in FIG. 1, a conventional laminated plate 3 used in a semiconductor device, on which an IC chip 14 is placed, is formed on a heat sink 1 constituted by a Cu plate. A method for manufacturing the conventional laminated plate will now be described.
2. Description of the Related Art
The laminated plate 3 is a so-called coppered laminated plate which is constituted by bonding a wiring pattern 12 formed of copper or copper alloy to the surface of a ceramic base member 11 such as alumina (Al.sub.2 O.sub.3) and aluminum nitride (AlN) and bonding a heat-radiating pattern 13 formed of copper or copper alloy to the undersurface thereof, using a high-temperature heating method such as a direct bonding method and an activated metal method. In FIG. 1, reference numeral 2 denotes an external electrode.
However, a wiring pattern has been reduced in size to meet the requirements for improving a degree of integration and a function of semiconductor devices, and has been increased in number to meet the requirements for increasing the number of outputs thereof. Inevitably, the wiring pattern 12 has to be positioned on the ceramic base member 11 with high precision. In order to position a number of wiring patterns 12 on the ceramic base member 11 with high precision, many hands and much time are needed, and manufacturing costs of the semiconductor devices are increased.